Nearly a year into President Biden’s term, a return to the Iran nuclear deal remains elusive — and a new cast of characters on Iran’s side of the table is driving a hard bargain.

Talks resumed in Vienna last week after a five-month hiatus following the election of hard-line President Ebrahim Raisi in June — only to adjourn Friday with little to show. Negotiators expect to begin anew this week.

The parties appeared to be on the cusp of a deal in June, before Raisi’s election paused the talks and lowered U.S. expectations for an agreement. Iranian hard-liners replaced more moderate officials who had been known quantities to the Biden administration. Five months later, several factors appear to be stacking against the possibility of progress.

As in previous rounds of negotiations aimed at returning Iran and the United States to compliance with the accord — President Donald Trump withdrew in 2018 — the two key countries have not been meeting face to face. Their diplomats camp out in different hotels while Europeans brief the Americans.

Biden pledged on the campaign trail to revive the 2015 nuclear accord. But relief from the blitz of sanctions the Trump administration imposed hasn’t come as quickly as Iranians had hoped.

As negotiations resumed, White House press secretary Jen Psaki called a return to the deal “our best available option.” So far, however, the talks have been heavy on distrust.

Raisi told French President Emmanuel Macron last week that “sending a comprehensive team to the negotiations shows the serious will of Iran in these negotiations.” But his chief negotiator, Ali Bagheri, who once called the nuclear agreement “a sick child,” said everything negotiated during the six rounds of talks between April and June was open for discussion.

The ball was “in America’s court,” he told Middle East Eye.

The United States does not wish to remove sanctions related to Iran’s proxy wars in the region and other issues. And it is impossible for Biden to pledge that a future administration won’t undo any agreement. European diplomats have warned that unless Tehran changes course quickly, negotiations were headed for collapse.